Individuals who are deaf, sound impaired, and/or speech impaired are able to communicate over a telephone network through a Telecommunication Device for the Deaf (TDD) such as a text teletypewriter (TTY) terminal. To communicate, a person types his or her conversation on a keypad of a terminal. Each letter is transmitted by an electronic code called Baudot. Baudot code is a 45.45 bps binary frequency shift keyed scheme that is half duplex, and without error protection. Each bit has a nominal duration of 22 ms and a character consists of 1 start bit, 5 data bits, and 2 stop bits. A mark, or “1”, is transmitted with a 1400 Hz tone. The space, or “0”, is transmitted with an 1800 Hz tone. The electronic code is sent from the transmitting TTY terminal to a receiving TTY terminal over telephone lines in the form of tones. The receiving TTY terminal transforms the tones back to letters on a display screen. The conversation typed by the person at the transmitting TTY terminal may then be read on the display screen of the receiving TTY terminal.
A person can also use a computer with a TTY modem to communicate with someone who has a TTY terminal. Computers generally operate in American Standard Code for Information Interexchange (ASCII). To communicate with a TTY terminal, a person who uses ASCII must use an ASCII/Baudot modem and related software to convert the ASCII code into Baudot code.
Wireless service providers currently support the transmittal of TTY information for emergency (911) calls. This may be done through a handheld mobile cellular phone. A need currently exist, however, for providing a system and method that can handle teletype information and that can be easily integrated into vehicular communication systems, such as an embedded in-vehicle Telematics system. This would provide a significant benefit to physically impaired individuals who desire to use a portable TTY terminal in a vehicle.
It is, therefore, desirable to provide an improved wireless communications in vehicles and method to overcome or minimize most, if not all, of the preceding problems especially in the area of communications for physically impaired individuals.
While the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined by the appended claims.